The present invention generally relates to a test trunk access controller and, in particular, relates to such a test trunk access controller having means for accessing a first subscriber line by means of a test trunk device in response to a signal from a second subscriber line.
In general, in order to perform the necessary maintenance and testing of subscriber telephone lines, a telephone company has a test trunk device that is connected, at one side thereof, to a maintenance and test center and, at the other side thereof, is connected to subscriber lines by means of a local telephone switch in such a fashion that, when a subscriber line is accessed, the subset connected thereto does not ring. By use of such test trunk devices, any subscriber line interconnected to the local switch can be accessed or, in fact, subscriber lines remotely connected thereto via other switches. The local switch referred to above is usually a central office switch although, alternatively, it can also be a Private Branch Exchange (PBX).
More recently, various telemetry or remote metering systems have been advanced that take advantage of these test trunk devices. That is, equipment is connected to a test trunk device that, when activated by a local equipment operator, connects the equipment to a subscribers line in a non-ringing fashion. Such systems require a dedicated line between the test trunk device and the equipment. These requirements present a considerable drawback both in cost and capacity. These drawbacks become more of a problem if the equipment is physically located at, or near, the central office switch, since, in such a location, physical space is at a premium.
Consequently, in an effort to avoid the expense and other difficulties associated with conventional telemetry systems, such as remote metering systems, it is highly desireable to provide a test trunk access controller that interfaces with the test trunk device at the local telephone switch and, nevertheless, allows use thereof via a conventional subscriber line.